FM 23-15 Basic Field Manual: Browning Automatic Rifle, Caliber .30, M1918A2 1943-06-30
"The Browning automatic rifle, caliber .30, M1918A2, is an air-cooled, gas-operated, magazine-fed shoulder weapon with bipod (flg. 1). It weighs approximately 20 pounds with sling. The ammunition is loaded in magazines of 20 rounds. The weight of the magazine when empty is 7 ounces; when filled, 1 pound 7 ounces."